<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <script>
        function getMax(arr) {
            var max = arr[0]
            for (i = 0; i < arr.length; i++) {
                if (arr[i] > max) {
                    max = arr[i]
                }
            }
            return max
        }
        var result = getMax([5,12,7,44,22,17])
        alert(result)
    </script>
</body>
</html>